Patients diagnosed with cancer are faced with costly and often painful treatment options. These treatments may be ineffective in a subpopulation of patients, and as a result, these patients endure these treatments without little or no therapeutic benefit. Some patients may react adversely to certain agents causing additional suffering and possibly death.
Ineffective treatment also is problematic because time is a key variable when treating cancer. A treatment provider has a far greater chance of containing and managing the disease if the cancer is diagnosed at an early stage and treated with a therapeutically effective agent. An agent may provide great therapeutic benefits if administered at an early stage of the disease; however, with the passage of time, the same agent may cease to be effective.
Lung cancer is an example of a condition where early diagnosis is key for effective treatment. Most lung cancers fall into one of two categories: small cell lung cancer and non-small cell lung cancer (NSCLC). NSCLC is the most common type of lung cancer. There are three main subgroups of NSCLC: adenocarcinoma, squamous cell carcinoma and large cell undifferentiated carcinoma.
Chemotherapy often is used for treating NSCLC. Erlotinib (TARCEVA®) is a chemotherapeutic agent indicated for second-line therapy of NSCLC after failure of at least one prior chemotherapy regimen and gefitinib (IRESSA®) is indicated for continued treatment of NSCLC after failure of platinum-based and docetaxel chemotherapies. As with many chemotherapeutic agents, administration of these drugs often causes deleterious side effects for the patient, and some patients do not respond well, or respond at all, to the treatment. Some patients thus undergo treatment with erlotinib or gefitinib and suffer the painful side effects only to later realize that the agent has not been therapeutically beneficial to their condition. In addition to the unnecessary suffering, critical time is lost in determining an alternative treatment.